In blood component therapy, the blood cells are often separated from the plasma by collecting the blood into a conventional, interconnected, sealed multiple bag blood collection system, followed by centrifuging the blood to separate the cells and the plasma. Thereafter, the plasma is extracted by being expressed through a sealed conduit into a "transfer pack", which is another bag of the multiple bag blood collection system. Following this, the plastic tubing is sealed and cut, to separate the plasma-containing bag, free from blood cells.
The separated bag full of plasma may then be used on a large scale basis as a raw material in the manufacture of blood components and other therapeutic items, such as serum albumin, antihemophilic factor, fibrinogen, gamma globulin, and the like.
In a typical blood plasma component manufacturing process, the plasma is pooled into a large volume container for processing to obtain the desired blood component products.
However, an inconvenience arises in that, typically, the plasma is initially collected in the multiple bag blood collection system by means of plasmapheresis or direct blood donation. The collected plasma is then typically pooled by opening the blood bags and emptying them into larger containers, which are then frozen and shipped to the blood plasma fractionation center. This provides the opportunity for contamination of the blood plasma due to exposure to the air prior to freezing, and also is quite inconvenient, requiring the opening of blood bags and pouring of them into larger containers for shipment.
At the same time, the typical polyvinyl chloride plastic used for blood bags is not a good material for freezing, since it is of significantly reduced strength at freezing temperatures, for example, -40.degree. C. and the like.
In accordance with this invention, a method and a multiple bag blood collection system are disclosed in which plasma may be effectively collected, separated from the blood cells, frozen, and then removed from its container while frozen, if desired on an automated basis. The collected blood plasma may be frozen in the bag in which it is collected, opened on a mass-produced basis, and optionally an automated basis, for removal of the frozen blood plasma for processing at the fractionation site.